What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

EMAG MAP HOOK-UP

Junk8

Member
I have the YIO-390EXP10 Lycoming engine installed. I ordered it with the EMAG already mounted. Anyone know where the MAP line gets hooked up? I have a Dynon MAP sensor on the firewall which is connected to the side of the engine. Does the EMAG line get "T"d into this line? Anyone else have this configuration?
 
Mike is right, T into the MAP line going to your EFIS MAP sensor; however, you need to add a restrictor in the line before the "T".

Perform a search on "Manifold line restrictor", there are a LOT of options,
 
I run a single Pmag on my O360 now but When I was running dual P mags I had a separate map line for each unit connected to the engine ports and that worked fine.:):)
 
Primer ports for cylinder 3 or 4

Thanks, I thought I might have missed something.

Be sure to put a restrictor in each line. Otherwise your P-mag's timing will bounce all over the place and will not be in time with each other. This is especially important since you have two different MAP sources.

The reason for the bouncing MAP readings w/o a restrictor is that when the intake valve closes it creates a high intensity, short duration positive pulse in the MAP line. The restrictor smooths these out.
 
We currently have the dimensions for a complete firewall forward fuel, oil, and PMAG hose setup with a dual PMAG installation for the RV-14. We are compiling a bit more data and pictures and will be releasing it officially in a few weeks. If anyone is ready before then or has any questions, we can build the packages but do not yet have them available on our website for online ordering.

Have a great weekend and happy building!
 
Last edited:
I have the hoses from Steve and Aircraft Specialty for my 14A and dual P-Mags and everything fits perfectly and is a nice upgrade from the stock hoses.
 
Hit this link for more on line restrictors. .040" is a good orifice size if you want to make your own. Any smaller will just clog faster.
 
Bill and all. We utilize -3 diameter hose for our PMAG MFP lines. The lines have a clear plastic extruded coating for abrasion protection. The stem diameter of a -3 fitting is very small and helps to dampen everything out. We have specially made -4 Flare fittings that fit into -3 hose so that we don't have to change out the fitting at the MFP sensor and can still keep the -3 diameter hose on a -4 diameter fitting. The same is true at the engine. We include a 45 degree steel elbow for the engine as the routing is a bit cleaner that way. In addition, we include the two AN Tees and the -3 fittings at the second tee end for attachment to the rubber hoses for the PMAGs.

This first image shows the lines and the tee setup at the engine and the MFP sensor

Pmag%201.jpg


This second image shows the unfinished system awaiting the rubber hoses to connect to the PMAGs.

Pmag%202.jpg
 
Last edited:
If I can add something--

The after crimp stem diameter of the -3 hose end is .079. Those that have used this setup, and on the original brazed tee we used to make, did not report any pulse anomalies so we left it as is. Yes, we can further restrict the orifice diameter if need be.
The question was asked why we changed from the brazed tee to the 'fitting'version. Well, honestly, making the brazed tee is labor intensive. Some clients had 1 PMag, some had 2, and some with 1, decided to add a 2nd one. With the brazed tee crimped inline, we would have to take that hose, cut out the single tee, add the dual port version, recrimp and return the hose. With the new 'fitting'version, using AN hose ends, its a simple matter of unscrewing the tee and replacing it with the dual port version. The outlet hose to the MAP sensor generally has enough slack that the extra length in the sender hose would matter.
One other thing---YES we have on some versions use teflon hose from the tee to the PMags. Since the tube on the PMag is sized for the vacuum hose included with the PMags, we decided to make a tube stub fitting that crimps on our teflon hose, and uses a short piece of the PMag hose for the connection. Gee--why would be do that? Well, some clients actually like the look of the braided hose, and weren't concerned over a few extra ounces of weight; the differences between the braided hose, and the vacuum hose. ( I guess if we had a PMag we could come up with a more improved version of this.) Yes, its does take alittle extra effort to remove the hose, and blow into it to set the timing, instead of just pulling off the vacuum hose.
One downside of this is it IS more expensive to use the teflon hose instead of the rubber vacuum hose for this system. Some of our clients have spent +-$2500 for the 2 PMags and WANTED something functional AND looked good. Another reason we changed to the 'fitting' version.

For you weight conscious builders--YEP plastic tees are available from most auto parts stores (Edelmann makes a large variety) for use with vacuum or plastic hose. Remember the plastic tees we had on our street cars in the early days? Yep they eventually break due to heat and cold----and some of you 'like' to fly in cold weather. Something to think about--as well as plastic in a FWF area. But with regular maintenance, its probably acceptable. NOT starting a flame war here!!

Tom
 
We updated our website to show more information about the PMAG setup for the RV-14 and RV-14A both in the single and dual configuration.

The info is located on the RV-14 Products page.

http://aircraftspecialty.com/rv-14.html

Here is a link directly to the Firewall forward information manual.

http://www.aircraftspecialty.com/PDF Documents/RV-14 FF.pdf

As always, we are happy to answer any questions or build custom sizes for different configurations.

Have a great weekend and happy building!
 
I have the hoses from Steve and Aircraft Specialty for my 14A and dual P-Mags and everything fits perfectly and is a nice upgrade from the stock hoses.

Did you change the configuration of the P-mags to match your engine? Neither the A or B configuration is close to the required timing for an angle valve engine.

PM me you phone number, if you want to talk about this.
 
Bill, this is something that I know nothing about as the engine was delivered by Lycoming with one Pmag and a std mag and went through the test runs so equipped. The Pmag was delivered in configuration B (jumper out) so I am guessing that's how they did the test runs. I talked to EMag and they confirmed the jumper should be IN on the engine (configuration A). Neither the factory nor Emag has said anything about neither configuration being correct. I'm not doubting you as I don't know this stuff and at this point I can only go by what Lycoming or Emag has said even though they differ.
 
MAP orafice question ?

I have 2 Pmags and nice braided -3 hose from TS with braised tee for soft hose attachments. I pressed an .040 orafice in the fitting at the cylinder head. Pmags work fine, but the EIC tells a curious story re: MAP stability. I even put more orafice in the MAP line to the sensor and no joy to stabilize the MAP reading on the EIC. The coolest idea I have seen on this tread is the ?hypodermic needle? for a long/ Small orafice. Hopefully this will help some one :)
 
I have 2 Pmags and nice braided -3 hose from TS with braised tee for soft hose attachments. I pressed an .040 orafice in the fitting at the cylinder head. Pmags work fine, but the EIC tells a curious story re: MAP stability. I even put more orafice in the MAP line to the sensor and no joy to stabilize the MAP reading on the EIC. The coolest idea I have seen on this tread is the ?hypodermic needle? for a long/ Small orafice. Hopefully this will help some one :)

I have Tom's excellent lines as well but not the EIC. I wonder why the "A" curve is not the default (jumper out) when nearly all installs are recommended to use it.

A small inline fuel filter can be used to buffer the MAP, too.
 
Bill, this is something that I know nothing about as the engine was delivered by Lycoming with one Pmag and a std mag and went through the test runs so equipped. The Pmag was delivered in configuration B (jumper out) so I am guessing that's how they did the test runs. I talked to EMag and they confirmed the jumper should be IN on the engine (configuration A). Neither the factory nor Emag has said anything about neither configuration being correct. I'm not doubting you as I don't know this stuff and at this point I can only go by what Lycoming or Emag has said even though they differ.
Even with the jumper in, the P-mags have way too much advance for an angle valve engine. Lycoming should know this but they haven't seem to have taken the time to learn the P-mags.

I'll PM you my number and you can give me a call so we can discuss your timing.
 
Last edited:
I have a Superior XP-400 with dual P-mags. I installed the jumper (less advance) to help keep temps under control during break-in. After about 30 hours when it was clear I did not have CHT issues, I removed the jumper for max advance. The engine provides great performance, excellent CHTs,and runs very well lean-of-peak with very nice efficiency. I?m curious why do you say this advanced timing is way too much for an angle valve engine?
 
We updated our website to show more information about the PMAG setup for the RV-14 and RV-14A both in the single and dual configuration.

The info is located on the RV-14 Products page.

http://aircraftspecialty.com/rv-14.html

Here is a link directly to the Firewall forward information manual.

http://www.aircraftspecialty.com/PDF Documents/RV-14 FF.pdf

As always, we are happy to answer any questions or build custom sizes for different configurations.

Have a great weekend and happy building!


This document has been updated to show the PMAG configuration adel clamp securing as well as the rubber PMAG hoses. In addition, we have now included the FM-150 servo configurations.

The single pmag pictures are not yet available, but the package will be nearly identical, except that one of the rubber hose fittings will instead include an AN-cap to plug the port. This will allow an easy change to a dual PMAG configuration down the road if desired.

http://www.aircraftspecialty.com/PDF Documents/RV-14 FF.pdf

Happy Building
Steve
 
I have a Superior XP-400 with dual P-mags. I installed the jumper (less advance) to help keep temps under control during break-in. After about 30 hours when it was clear I did not have CHT issues, I removed the jumper for max advance. The engine provides great performance, excellent CHTs,and runs very well lean-of-peak with very nice efficiency. I’m curious why do you say this advanced timing is way too much for an angle valve engine?

That is not a good setting for your engine and you could be giving up some power, and risk damaging your engine.

What is the recommended timing for your engine? I belive it and the IO-360 & 390 angle valve engines are designed for 20° BTC timing settings.

The "Jumper In" A configuration starts at 26.6° and the "No Jumper" configuration starts at 30.8° BTC for high power operations, such as takeoffs and they advance from there.

With parallel valve engines, we have been able to demonstrate better performance and cooler CHT's with slightly reduced advance settings.

I suspect you will pick up some performance and reduced fuel burn, if you customized your timing configuration close to the recommended 20° BTC.

I will be happy to work with you (or anyone else with an Angle Valve engine), to prove this out. Just PM your number, if you are interested.
 
Last edited:
Hi Bill:

This thread prompted me to do some digging on VAF. Last evening I invested an hour in an 18 page thread on the topic from 2013/14 (one you participated in). With this background, I am now intrigued enough to do some more experimentation and evaluation.

During break-in, I used the A curve with manifold pressure disconnected for the first few hours. When I didn't see a single CHT over 400? despite the high power settings, I connected the manifold pressure and after more hours, switched to the B curve. During my break-in, I was adding wheel fairings piece by piece so performance changes were impossible to attribute.

With 180 hours, I now get 170 kts TAS at 7,500 on 8.2-8.3 GPH, CHTs in the low 300s and never over 400 no matter what - quite a bit better than I saw on my RV6 and much better than I expected on this larger airplane, so I am (was?) quite happy. However, after reading all the discussion (older thread) I will give the A curve a serious evaluation now. Unfortunately, tomorrow the airplane goes into the paint shop so my testing will have to wait. I will contact you in about a month.
 
Keith,
Here is the good news, you will not hurt your engine by moving the timing down to 20?, where it belongs. Running more advance can cause damage.

Check your PM's.
 
As info I have a TMX360 8.5 comp. ratio. Originally 113 eMag/pMag on my RV7. An early issue with the pMag resulted in a circuit board change. Last annual I sent them in for maintenance & upgraded the eMag to PMag. The circuit board on that unit wasn?t upgradable to the latest software. I decided to remove the jumpers & time them both 2 teeth after TDC. (149 tooth ring gear) This appears to work well & starting is really smooth. It appears to be 1 or 2 knots faster LOP @ 8gph & 8500ft.
Bob
 
As info I have a TMX360 8.5 comp. ratio. Originally 113 eMag/pMag on my RV7. An early issue with the pMag resulted in a circuit board change. Last annual I sent them in for maintenance & upgraded the eMag to PMag. The circuit board on that unit wasn’t upgradable to the latest software. I decided to remove the jumpers & time them both 2 teeth after TDC. (149 tooth ring gear) This appears to work well & starting is really smooth. It appears to be 1 or 2 knots faster LOP @ 8gph & 8500ft.
Bob
Bob, you are still running too much advance.
The B curve (They are the same on both boards) starts at 30.8. So by timing them two teeth after TDC, you are essentially running 26* timing, just a little less than the A Configuration.

However, the 114 P-mags (and your 113's with the 114 boards) fires the plugs at 4 degrees after TDC for starting (whenever below 200 RPM). This means you are at risk of a kickback with your setup.

It is best for you to put the jumper in and set the P-mags at TDC. (Assuming your TMX360 is a parallel valve O-360, 8.5:1 is the standard compression, it is even better to reduce the A configuration setting by 1.4 degrees.)
 
This confuses me a little. Before the upgrade I would get an occasional kickback when timed with the jumper at TDC or even a half tooth retarded. Once I realized I needed 4 deg. retard at start I figured I?d just remove the jumper & set the retard by 2 teeth for 4deg on the older board & 8deg on the newer. I figured this would get me a running curve that?s retarded a little from the A curve on both. The start is really nice and spins up off the starter in 3 or 4 hits kind of like a rough running turbine. It seemed to make sense which is why I posted. ? Bob
 
There are a couple of things that can cause a kick back, including too much fuel when priming the engine.

The older software, pre-version 40, would fire the plugs at TDC when starting. It wasn't until V40 came out that they started firing the plugs at 4 degrees after TDC when below 200 RPM.

You might be firing just after TDC, as the resolution for setting the timing on the flywheel really isn't that great.

It is my recommendation to program the P-mags and set them to TDC. If you go this route, document the timing setting in your engine log book so you know exactly what they are. That way, if you ever send the P-mags back in for a checkup they will come back reset to factory defaults. Then you can reset them to your desired configuration.

Programming them is easy enough to do with the free EICAD program from EMAG; however, it will require you to buy a USB to Serial converter.

That you can rip down here to SC86 and we can do it here. All you will have to do is remove the cowls. (We are a bit far from Nebraska though.)
 
Back
Top